docs: explain why clients are not in the topics

README.md

@@ -18,6 +18,7 @@ Messages are routed using either a publish/subscribe or broadcast mechanism.
 For published messages, the message is published for a given a topic. 
 
 Clients create a subscription (stored in their config) to a topic pattern which may include wildcards. 
+
 It's important to note that the client config documents the subscription. To change a client 
 subscription it must be updated with the backbone.
 
@@ -35,6 +36,8 @@ The `destination` field should be set to `broadcast` for any messages sent using
 Because the `destination` field is a topic it defines what the message relates to - not 
 who the intended recipient is. 
 
+This means that the clients are not typically represented in the topics. A client publishes a message about a platform and subscribers interested in that project, platform or message type will receive that message.
+
 ### Structure
 
 `<prefix>.<operator>.<platform_type>.<platform_identifier>.<to_platform|from_platform>.<message_type>`